MoS2/Quantum Dot Hybrid Photodetectors on Flexible Substrates

Abstract

MoS2 is a semiconducting transition-metal dichalcogenide and an attractive candidate for optoelectronics and flexible electronics due to its strong excitonic interactions, low dark current (IDark) and high mechanical strength. Photo detectors (PDs) based on MoS2 have been demonstrated with high responsivities and low IDark [1]–[3]. However, long response times, often in the range of several seconds, severely limit their use for imaging applications. Hybrid structures made of MoS2 and colloidal quantum dots (CQDs) have been shown to improve the response times down to the ms range [4]. These devices were made from exfoliated materials and on rigid substrate. Here, we present hybrid MoS2/CQDs based PDs with high performance using a scalable fabrication approach on flexible polyimide (PI) substrates with metalorganic vapor phase epitaxy (MOVPE) grown MoS2. Our MoS2/CQDs PDs show fast response times in the ms range and withstand mechanical strain, which provides evidence that our scalable process on PI substrates is a promising approach towards flexible optoelectronics, e.g. wearable sensors or healthcare systems.